1. Field of the Invention
The present invention relates to an etching method and an etching apparatus of carbon thin film for etching a carbon thin film formed on a surface of a sample made of silicon, silicon carbide and the like.
2. Prior Art
For example, in the case where a carbon thin film is formed on a surface of a silicon substrate which is a sample, plasma etching is mainly used for removing the carbon thin film.
However, in such an etching of carbon thin film based on the plasma etching as described above, it was impossible to prevent the sample from getting damaged because energy particles come into collision with the surface of the sample. Damage in a sample used to be possible be recovered to some extent by annealing of post process, however, annealing for recovery of damage was sometimes not possible to be conducted in case that the etching step of carbon thin film is close to the final step in the process. This has been considered to be a serious problem in a manufacturing process of semiconductor devices.
In addition, since an etchant that chemically removes a carbon thin film has not existed yet, the above-described plasma etching which will cause some damage on the surface of a sample is in use.
The present invention was devised in consideration of the above circumstances, and it is an object of the present invention to provide an etching method and an etching apparatus of carbon thin film which, in etching to remove a carbon thin film formed on a surface of a sample, will not cause a damage on a surface of the sample, without requiring any special apparatus (such as vacuum pump) which has been required in plasma etching and the like.
An etching method of carbon thin film according to the present invention is an etching method of carbon thin film for removing a carbon thin film formed on a surface of a sample, and configured to etch the carbon thin film by heating the sample to 550xc2x0 C. or higher in an atmosphere of an inert gas into which a predetermined proportion of oxygen gas has been mixed.
In addition, the etching apparatus of carbon thin film according to the present invention includes a sealed reaction chamber in which a sample formed with a carbon thin film on its surface is to be set, a gas feed means for feeding an inert gas into which a predetermined proportion of oxygen gas has been mixed from one end of the reaction chamber to the interior of the reaction chamber, an exhaust means for discharging carbon dioxide gas from the downstream side of the inert gas fed from the gas feed means, and a heating means for heating the sample to 550xc2x0 C. or higher.